Driller



Jan. 1, 1952 w, w -r 2,581,258

DRILLER Filed Aug. 12; 1945 3 Sheets-Sheet l INVENTOR. k/y m/wa Jan. 1, 1952 DRILLER Filed Aug. 12, 1945 3 Sheets-Sheet 2 J. w. KARWEIT 2,581,258

Patented Jan. I, 1952 UNITED STATES PATENT OFFICE John W. Karweit,

assignments, to

Skokie, Ill., assignor, bymesne Ex-Cell-O Corporation, De-

troit, Mich., a corporation of Michigan Application August 12, 1943, Serial No. 498,314

10 Claims. i

The present invention relates to the art of drilling a hole in a machinablev material such as metals, alloys, elastomers and plastics, with a machine tool drill such as a twist drill.

Reference is hereby made to my copending applications Serial Nos. 484.612 (now Patent No. 2,453,136) and 455,417 (now Patent No. 2,453,137) to the extent that a better understanding of the principles herein incorporated may be had, the disclosures of these madea part of this application.

One of the objects of the present invention is to provide an attachment or construction for power driven machine tools by which a drill may be supported against or for rotation to oscillate axially in a predetermined stepped or controlled relation tation of a work piece anddrill produced at the cutting edge drill which are ofa regulated uniform size and shape, in order to be able to clear the drill or flutes without packing and without scoring the side walls of the hole being formed.

Another object of the invention is to'provide a rugged compact construction by which the purposes of the inventioninay be performed with large drills under circumstances in which the feed pressures to be borne by the device may be as much as 3000 lbs.

to the relative r whereby chips are or edges of the Another object of the invention is to provide a construction wherein'a drill may beoscillated axially a small fraction of an inch while the end thrust pressures exerted upon the drill are transmitted between the cooperating parts along a line disposed within the confines of the spindle.

Another object of the invention is the provision of a construction which can be adjusted or made to provide a predetermined relation between the reciprocation of the drill and the relative rotation of. the drill and workpiece.

A further object of the invention is to balance and end thrust pressureefiort for a drill upon the opposite side of the axis of relative rotation between the drill and work piece, with a single cam and follower engagement for reciprocating the drill.

These being among the objects of the present invention, other andfurther objects will be apparent from the drawings, the description relating thereto and the appended claims.

, Referring to the-drawings:

Fig. 1 is a side elevation of a turret lathe upon the turret of which a preferred embodiment of the invention is installed either as an attachment or as original equipment.

applications being hereby and substantially manner and in a Fig. 2 isa 'longitudinal section through the preferred embodiment shown in Fig. 1;

Fig. 3 is a section taken upon the lines 33 in Fig. 2;

Fig. 4 is a vertical section taken through an attachment illustrating another form of themvention which would be employed if the-turret lathe were provided with a rotaryspindle, or could be used upon a large drill pressto take drills as large as two inches in diameter.

Fig. 5 is a section taken upon theline 5-5 of Fig. 4.

Generally speaking, the size of the. chips. are determined by repeatedly lifting the feed pressure and'the drill during the feed traverse to allow the edge or edges of the drill to sever from the work piece the chips being formed and then returning the drill to its cutting position to make other chips to be'severe'd like the first. Preferably, the cutting edges are lifted slightly from cutting engagement at predetermined intervals, which intervals are stepped to the relative rotation of the drill and the workpiece so that the chips are fairly uniform in size and shape and are suitable for quick and complete removal from the hole so that they are. released quietly and safely at the mouth of the hole for disposal and reclamation.

In operation, the. duration of the cutting engagement with the work piece between sever.- ances just mentioned, may be variedwith the material being drilled and in the present invention can be varied or adjusted while the drilling operations are way of example, the duration of the cutting engagement should be long enough for a cutting edge to cut through that .point upon the work piece where a preceding severance was had within a revolution of the drill preceding, the next severance to be made.

.This is accomplished upon a turret lathe as illustrated in Figs. 1, 2 and 3. In Fig. 1 a turret lathe is shown at IU which is provided with the usual head H and collet chuck [2 on .the head spindle l3 to support and rotate a work-piece I 4. The speed at which the work piece I 4 is rotated is controlled by means of a manual speed selector l5 which controls either agear box-or a multispeed motor (not shown) by which .the head spindle i3 is driven.

The bed of the lathe is shown at 16 upon which is mounted for forward and reversetraverse a carriage H. The carriage I! is traversed on the bed It either manually or automatically. Manual feed is accomplished by the hand wheel proceeding. In general, and by 2| mounted upon a carriage apron 22. Automatic feed is accomplished by means of a shift lever 23 and reversing lever 24 which control a mechanism not shown that cooperates with the threads upon the worm feed shaft 25 driven from the gear box 26 as controlled by a speed preselector or lever 21. Below the bed an oil catch 28 is provided which drains to an oil sump (not shown) from which the oil is pumped by pressure to flood the tool and work piece.

The carriage I1 carries a rotatable turret l8, preferably of hexagonal shape, adapted to hold and support different tools, such as reamers, counterbores and cutters (not shown). Upon one of these faces is mounted an embodiment of the invention as actuated by an electromagnetic means, such as an electric motor 20.

The speed of the motor is controlled by a centrifugal switch 35 (not shown) which is adjusted bya manual control 3i and is placed in operation only when the turret is in one par ticular position as, where a drill is located in working position for the work piece 14. This operation of the motor 23 is controlled by switch contacts 32 which are brought into engagement with each other when the working position is established.

As more particularly shown in Fig. 2 the drill 33 is an oil fluted twist drill provided with a tapering shank 34 that is received in a supporting element 35 as held against rotation by a tang and socket assembly 36. The oil flutes 31 open upon the face of the shank 34 as at 38 wherethey are in register with an internal groove 40 in the supporting member to receive a supply of .oil from a pressure line 4|. The supply of oil is controlled through a suitable valve mechanism, which is not shown, to permit the oil to flow into the drill only when the drill is in working position with respect to the work piece l4. 7

The drill support 35 is reciprocably mounted upon .a supporting element 42 that in turn is received in a socket 43 upon the turret 18 where a it is locked in place by means of a set screw 44. Oscillation of the drill support in the supporting element 42 is had by means of a cam 46 and follower 41 which will now be-described.

A A,,radially disposed slot 48 is cut through the central portion of the driller support 35 to receive a frictionless bearing 50 upon the outer race 49 of which is pressed the follower 41. A bore is provided as at 5| (Fig. 2) to receive a shaft 52 which supports the inner race 53 of the bearing 59. The shaft 52 is held in place by a pin 54 and the end thrust effort exerted upon the drill 33 is borne by the shaft 52 and bearing 50 to the follower 41.

A second bore is provided as at 55 in the drill support 35 to register with a bore 56 in the supporting element 42. In these bores is disposed a shaft 51 journalled upon the supporting member 42 by frictionless bearings 58 which are held in place by a, cap nut 59 at one end and a transmission housing 6| at the other end. The cam 46 comprises a relief cut in the outer face of the shaft 51 preferably within an arc of 60 degrees and to a depth of from .010 to .035 of an inch to engage and cooperate with the track or follower 41 upon the bearing 59. Thus, the peripheral face of the cylindrical shaft 51 defines a dwell area or portion extending over the major portion of the circumference, and the relief defines an offset portion, the dwell portion and relief portion constituting the complete cam.

Ears 69 sliding in slideways 19 upon the supporting element 42 carry the torque strains exerted upon the drill support 35.

The supporting element 42 is secured rigidly to a secondary element 59 by means of screws 62. This secondary element is provided with a A shank 63 which is engaged by the lock screw 44 upon the turret head 18. The end thrust effort existing at the follower 41 is transmitted to the turret 18 through the shaft 51, the bearings 58 and the secondary element 59.

A socket G4 is provided in the secondary element 59 to receive in reciprocable relationship a reduced end 65 upon the drill support 35, and a conical centering pin 66 is mounted in the secondary element as urged by a compression spring 61 to carry a conical portion 68 thereof into engagement with a conical socket 10'upon the reduced end 95.

The track 41 and cam 46 are urged to cooperate with each other by means of a compression spring 1i resting against a shoulder 12 upon the drill support element 35 as held in place by a gland nut 13. With this construction the drill support 35 is held in alignment between the turret head I8 and work piece M by the supporting element 42 and the secondary element 59 for reciprocable movement as controlled by the cam 46, follower 41 and the spring 1!.

Reciprocation of the drill support is accomplis'hed by rotating the shaft 51 and although there may be different ways of doing this, two preferred forms are shown, one of which is accomplished by an independent prime mover if the drill 33 is held against rotation, while the other is by a gear arrangement (see Figs. 4 and 5) if the drill is rotated.

In order to accomplish rotation of the shaft 51 by the motor 28 a worm wheel 14 is mounted upon the upper end of the shaft 51 where a worm screw 15 engages and rotates it as driven by the motor 25 through a flexible shaft 16 and a detachable connection which comprises a detachable tang and groove assembly 11 held in engagement by a cap nut 18. The speed at which the shaft 51 is rotated determines the number of reciprocations imparted to the drill and this can be varied by means of the speed control 3| upon the motor 20.

With this arrangement whenever the drill 33 is brought into working position with respect to the work piece l4 the contacts 32 are closed to start the motor 20. The speed of the motor is then adjusted by the hand adjustment 3i in relationship to the speed at which the work piece 14 is rotated so that the chips formed by the drill 33 as reciprocated by the follower 41 and cam 46 will be of a size sufficiently small to clear the flutes of the drill easily, yet not large enough to bind and score the walls of the hole being cut.

This adjustment and the speed of the motor 20 enable the operator to provide the best chip size for any given material merely by a single adjustment. After becoming familiar with the invention an operator will be able to adjust the speed of the motor 25 to provide the optimum results available for a given drill and a given material of which the work piece [4 is made. By way of assisting the operator, however, in placing the invention into operation it is suggested that the reciprocation of the drill 33 should be once each relative rotation between the work piece and the drill if the drill is a double edge drill such as twist drills. In event beveled :gear184 J is,

.a .drill 33 ;:is i used which .zhas. avsingle cutting edge, esuch as a rifle: drill, it: is .suggested.:that the reciprocation should be: slightlywless :frequent than-once each relative :rotation, it-being desirable thatthe. cuttingaedge' of .the: drill" cut away therhumpwleft' by. a prior reciprocation:before leavinganother; one in a subsequentmeciprocat-ion.. 'In :"the embodiment shown :in Figs. .c kan'd- :5, a drillsupportgis-sshownzat 8o asiprovidedqprefierably-withya Morsetbl taper 8| toiireceivezthe tapered t :shanks: ofra larger ran go: of :drills :with or without adapters, and the supportingsele ment 242a as Jshownrat 82 '.-is;.providedtat .the-xtop withta Morse #3 .itaper- 831to f'beztreceived in Morse #3 :or 1 4 spindle tapers :with z or u-with'out adapters asiithe 'caseamayrbe. In this "particular embodiment :a stationary provided:toaengage'aiibeveled upon *the. shaft .5121. 1 Thus" as gearf'flfi :mounted the 'rotatafithe shaft 25la:-is compelled. to :rotate by Qtheaaction of the gears'rfikandlfi and the speed ratio betweenthe gears 84 and 85 est'ablishes the relation -.that the: number of reclprocations bear to 'the' number of revolutions "of 1 the drill in a "given time. Itispreferred with this arrangement-that the gear 85 be"slightly smaller or larger: than the gea1 84 to provide a slight creep of "the oscillation point one 1 way or' the other.

"in order tozhold the-gear 84 station'ary a 'housing lldis provided and supplied-with 'an outrigger s'l that rides against astationary part of -a power tool such the starrda'rd ota drill press (notshown) 1' The housing comprises an upper part-'88 bo1t'ed to a lower part --9 fl by m-eans of bolts ll l as carried by -a frictionless bearing 92- 'held in-place' by a "cap =93 'having a suitable *grease seal 94 -cooperating with a cylindrical-surface' 95 just be low the'Morse-#3'-taper 83. At its lower end 96 the housing 86 is provided with a bearing 91 which journals the drill support 80 with respect to: the housingfifiya suitable .oil'seal being indicated at 98.

Otherwise-thmparts 'shown'in Figs. 4 and 5 which are similar or correspond to parts described in connection with the-embodiments illustrated in -Figs. 2-and-3 are providediwithflike numbers with the suflix' d constructionsthe feed thrust is borne along a substantially direct line from" the supportpoints to-the-tip of'the drill-33.

"In theembodimentshown "infFigs. 1 4 and; 5 the bearings employedto'support theccamrand fol-lower elementsare-need1e*bearings insteadiof ball bearingsand centrifugaleffort exerted upon the shaft 52a because of the bodily rotation thereof is absorbed and counteracted by anend thrust bearing I00 held in place by a castellated nut lill locked by a cotter pin I02.

Thus, having described the invention and certain modifications thereof, it will be readily apparent to those skilled in the art that various and further modifications and changes may be made to embody the objects mentioned without departin from the spirit and substance of the invention the scope of which is commonsurate with the appended claims.

What is claimed is:

1. A device for drilling a machinable material which includes a drill support, an element supporting the drill support for relative axial movement and against relative rotation between them, means for feeding said element axially of supporting .aelement-wand 'rthe drill supportsaiddrill supports, cam unltrhavingadwell-t-portion and an' oflsetcamportiomssaid ofiset portion extending only through a minor portion sof the ca-m -circumference,= a followerunit one of said units being supported by the element, the other of said units being supported -by thedrill support, said units .coacting with eeach other at a point of engagementdisposed'withinthewaxial projection of the --element-.supporting-. theudrill support whereby the "feed .thrustveifortmpon the; drill iszborne within thezconfines -of.-said element;

22.-A device for drilling "-a a' machinable ma terials including. a holderifor' a machine tool drill, an element: for supportingzthe holder-against radial: displacement: :and for '2 relative '"axi'ali'displacement with :respectrto thez'axisi of theildrill. a rotatable element disposed-"withothe axis thereof at ani'anglei tO thEHXiSTOf' thB drill, a second rotatable element 'journalled upon fthe holder: and engaging :the first element at :a point approximately in f line with the axis :of thec'drill', me'ans' for rotating one of :said relements: 'by po'sb tiveifaction, a ."cam =upon'wone 'tof the elements having I a relief adapte'd to be "engaged by the other: of the elements, and means forf'urgingithe element on. the holder into contact 'with the other element.

3. A device for drilling atmaohinable material including a holder I for a 1 machine: tool i" drill; an .lement" for supporting'ithe holder ifor Prelative axial displacement z with respect totthe "axis *ff the drill, 1 arotatable-element Jdispo'sedrwitl'uthe axis thereof at an angle to 'the axis of the idrill, a second rotatable element journalledlupon 'the holder an'd engaging the first-elen'lentvat azpolnt approximately in line" with the axis "of the dr'ill, meansfor rotating one" of said iile'ments icy :positive 4 action including a speed 1 controlled driving mechanismya cam upon one "or the 1 elements having a relief adapted "to be engaged-by time other oi the elements and means for urging the rotatable elements 'into contactwith each other.

device 'for firilling amaohinable material including "a holder for a 1 machine toordrin; an

"element for supportingthei'holder' for relative axial displacement in line 'with' theaxis "ofth'e drill, -a rota-tab1e element disposed with 'the axis thereof-at an angle' to-th'e axis of thed'rlll, a second' rotatable'element journal-led upon'the hol'der and cooperatin'g with the fiist element, means' fo'r rotating one 'of said elements bypositive action including a transmission interconnecting thesupporting element and'said 'rotated element; a cam upon one of-theelements' having a relief adapted to be en a ed by the other of the elements, and means for urg'i'ngthe'holderto carry theelements carriedby it'into contact withthe' other-element.

5. A device of the type described for rotary drilling a machinable material including a rotating supporting member, a supported member mounted for reciprocation and adapted to receive in supporting relation a drill, means for rotating the supported member and a work piece with respect to one another, cam and follower elements, one of said elements being mounted upon one of the members and the other of said elements being mounted upon the other of said members, means urging the members to reciprocate with respect to each other in relation to the action of said elements whereby the feed thrust pressure upon the drill is borne by the members and elements, and means for rotating one of the elements with respect to the other at a speed different than the speed of relative rotation beoperative surfaces thereon of unequal lengths.

6. A device of the class described for drilling a machinable material, a drive member adapted to be mounted for rotation with a spindle and having a socket in the end, a driven member received in said socket for rotation with the drive member and for reciprocation with respect to the drive member, a shaft journalled in the drive member and having a cam thereon, said cam having an offset duration of a minor portion of a revolution, a follower mounted in the driven member to cooperate with the shaft to reciprocate the driven member, means for rotating the shaft in relation to the rotation of the driven member, and means urging the follower to cooperate with said cam.

I. A device of the class described for drilling a machinable material, a drive member adapted to be mounted for rotation with a spindle and having a socket in the end, a driven member received in said socket for rotation with the drive member and for reciprocation with respect to .the drive member, a shaft journalled in the drive member and having a cam with a dwell thereon and an ofiset duration of a minor portion of a revolution beyond said dwell, a follower mounted in the driven member to cooperate with the shaft to carry the feed pressure on the dwell, means for rotating the shaft in relation to the rotation of the driven member including a transmission between the shaft and one of said members, and means urging the follower to cooperate with said cam.

8. A device of the class described for drilling a machinable material, a drive member adapted to be mounted for rotation with a spindle and having a socket in the end, a driven member received in said socket for reciprocation therein and rotation with the drive member, a shaft journalled in the drive member and having a cam thereon, a follower mounted in the driven member to cooperate with the shaft to reciprocatethe driven member, said cam having an offset duration of approximately 60 of relative rotation between it and said follower means for rotating the shaft in relation to the rotation of the driven memberinoluding a transmission between the shaft and one of said members having other than a one to one speed ratio, and means urging the follower to cooperate with said cam.

9. For use in a machine tool having two parts rotatable and traversable with respect to .each other, a device for drilling a machinable material comprising an elongated member adapted at one end to be received in supported relation upon one of the parts, a shaft journalled on said memher and having a cam track thereon with a dwell over a major portion of the shaft circumference and a radially offset cam area over a minor portion of said circumference, a second member adapted to support a drill and being reciprocably mounted with respect to the first member, a cam folower carried by the second member and cooperating with said cam track, means for rotating the shaft to oscillate the drill within a minor portion of a revolution of the shaft, and means upon said other part for supporting a work piece.

10. A chip comminutor for a driller, said comminutor comprising a supporting sleeve element receivable in axial feed traversable relationship upon the driller, a supported element adapted to receive a drill and reciprocably mounted upon the supporting element for relative movement along a line coinciding with the line of feed traverse, a housing carried by said supporting element and supported against rotation, means for moving said supporting element in said feed traverse, means for jointly rotating said elements, and means for reciprocating said elements with respect to each other in the course of said feed traverse, said last mentioned means including a rotary cam journalled in said supporting element on a transverse axis, said cam having an offset constituting a minor portion of the cam path, a follower supported on said supported element for coaction with said cam, resilient means for urging said cam and follower into engagement with each other, and a gear transmission interconnecting said housing and said cam, and having a ratio other than one-to-one to the rotation of said elements, whereby upon rotation of said supported element a chip comminuting oscillation is imparted to the drill in stepped relation to the rotation of the drill.

JOHN W. KARWEIT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Bates Sept. 7, 19.43 

